PCM - Cold Start Engine Sag
NO: 18-25-95GROUP: Vehicle Performance
DATE: Jun. 30, 1995
SUBJECT:
Cold Start Or Partial Cool Down Engine Sag And/Or Momentary Engine RPM Drop When Coming To A Stop
MODELS:
1995 (JA) Cirrus/Stratus
NOTE:
THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH A 2.4L ENGINE AND AUTOMATIC TRANSMISSION BUILT BEFORE JUN. 19, 1995 (MDH 06-19-XX).
SYMPTOM/CONDITION:
Moderate to heavy engine sag or hesitation on a cold start (50 to 80 degrees F. ambient) or after partial cool down (100 degrees F. engine temperature). Condition is most noticeable on light to medium tip-ins for the first 1-2 minutes following start.
Momentary engine RPM drop when coming to a stop or when cooling fan engages.
DIAGNOSIS:
Using the Mopar Diagnostic System (MDS) or the Scan Tool (DRBIII) and appropriate Diagnostic Procedure Manual, verify that all engine systems are functioning correctly. If Diagnostic Trouble Codes (DTC's) are present, record them on the repair order for future reference and repair as necessary. Verify condition(s) by:
- Allow fully warm vehicle to soak until coolant temperature drops to 100 degrees F. Start engine and perform light tip-ins.
- Allow vehicle to soak overnight. Start engine and perform light tip-ins.
- Perform light, moderate and heavy stops from 30 MPH. Observe for momentary engine RPM drops as engine decelerates to idle.
- Allow engine to idle in neutral with NC off. As engine reaches operating temperature cooling fan will engage. Observe for momentary engine idle drop below 700 RPM.
^ If any of the above conditions exist, perform the repair procedure.
EQUIPMENT/PARTS REQUIRED:
1 CH6000 Scan Tool (DRBIII)
1 CH7035 General Purpose Interface Bus Cable (GPIB)
1 CH7000 J1962 Cable
1 4669020 Label - Authorized Software Update
1 4275086 Label - Authorized Modification
REPAIR PROCEDURE:
This bulletin involves selectively erasing and reprogramming the Powertrain Control Module (PCM) with new software (calibration change).
NOTE:
MDS AND DRBIII ARE REQUIRED TO PERFORM THE FOLLOWING REPAIR. MDS MUST BE OPERATING WITH RELEASE 16 OR HIGHER AND TIL 1083 OR HIGHER INSTALLED.
1. Connect the MDS and DRBIII to the vehicle and power them up.
2. Use the arrow keys and select # 2 MDS DIAGNOSTICS on the DRBIII MAIN MENU Screen.
3. Use the arrow keys and select DIAGNOSTIC MENU on the MDS, then press NEXT MENU.
4. Use the arrow keys and select CONTROLLER PROGRAMMING on the MDS, then press NEXT MENU.
5. Use the arrow keys and select PROGRAM CONTROLLER PART on the MDS, then press NEXT MENU.
6. Follow the steps presented on the MDS and DRBIII which will allow the DRBIII to obtain the current part number of the PCM.
7. The MDS will display the part number of the PCM on the vehicle and the appropriate replacement part number, then press NEXT MENU to begin programming.
If the PCM on the vehicle has already been updated or programmed, a NO UPDATES AVAILABLE message will be displayed. Check the part number of the PCM on the vehicle and compare it to the part number displayed. If the PCM has already been updated, then a system problem actually exists and should be corrected.
8. The MDS and DRBIII will prompt the operator for any action needed during the remainder of the programming process.
NOTE:
THE FOLLOWING STEPS ARE REQUIRED BY LAW.
Chrysler Authorized Software Update:
9. Type the necessary information on the "Authorized Software Update" label, P/N 4669020. Attach the label to the PCM and cover the label with the clear plastic overlay.
Chrysler Authorized Modification Label:
10. Type the necessary information on the Authorized Modification Label and attach the label near the VECI Label.
POLICY:
Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
Labor Operation No: 08-19-42-99 0.5 Hrs.
FAILURE CODE: FM - Flash Module